New Beseler VC head on older (blue) 23C

I have heard of this being done before, but does anyone know what, if any modifications need to be done to an older blue 23C (series 2) enlarger to mount the 23CIII Variable Contrast head on it? I'm sure the condenser stage and upper bellows get removed, but can anyone provide any further information on this? I haven't bought the VC head yet, I'm sure if I had one in hand it would be pretty easy to figure out.